Exposure apparatus

ABSTRACT

An exposure apparatus includes a projection optical system for projecting a pattern of a mask onto an object using a light with wavelength of 20 nm or less from a light source, and first and second accommodating parts for accommodating the projection optical system and the mask or the object, said first and second accommodating part has different pressures, wherein said a Ps/Po≧100 and Ps≦10 −3  Pa are met, where Po is the pressure of the first accommodating part, and Ps is the pressure of the second accommodating part.

BACKGROUND OF THE INVENTION

The present invention relates generally to an exposure apparatus thattransfers a pattern of a mask (reticle) onto an object such as a singlecrystal substrate for a semiconductor wafer and a glass plate for aliquid crystal display (“LCD”), and more particularly to an exposureapparatus that exposes an object using a light with a wavelength of 20nm or less in a reduced or vacuum environment. The present invention issuitable for an exposure apparatus that uses an extreme ultravioletlight (EUV light) (referred to as an “EUDV exposure apparatus”hereinafter).

Along with the recent demands on finer processing and improvedeconomical efficiency, the further improvement of resolution andproductivity of the projection exposure apparatus has been increasinglyrequired. In the improvement of resolution, shortening the wavelength ofexposure light is general, and recently, an EUV exposure apparatus usingEUV light with a wavelength of 10 to 15 nm has been proposed. The EUVlight is easily absorbed by air and helium etc., a conventional EUVexposure apparatus accommodates an optical system, mask and object in avacuum chamber, and exposes with the inside maintained to a vacuum orreduce environment (referred to as only a “vacuum environment”hereinafter).

However, when the mask and object are carried into and carried out ofthe vacuum chamber, an atmosphere flows into the chamber and the vacuumenvironment is broken. In addition, it takes a long time to form again apredetermined vacuum environment by evacuating the vacuum chamber.Moreover, organic matters generated from a resist on the objectcontaminate the optical system during exposure. The contaminated opticalsystem causes various problems, such as a decreased light intensity andthroughput, a non-uniform distribution, and a lower resolution etc.

An EUV exposure apparatus that divides the vacuum chamber into pluralareas (accommodating parts) and accommodates the mask, object andoptical system in different accommodating parts has been proposed (see,for example, Japanese Patent No. 2,691,865 and Japanese PatentApplication, Publication No. 2003-332214). The separate accommodatingparts enable, for example, the accommodating part that accommodates theoptical system to maintain the vacuum environment even when the objectis carried out of the vacuum chamber to exchange the object. As aresult, after the object is exchanged, only the accommodating part thataccommodates the object may be evacuated. Therefore, a time periodnecessary to form a predetermined vacuum environment shortens, and theoptical system is protected from contaminations during exposure.

However, Japanese Patent No. 2,691,865 arranges a light-transmittingthin film window between the accommodating parts, and causes thedecreases of the light intensity and throughput because the thin filmwindow absorbs the exposure light. An exposure apparatus of JapanesePatent Application, Publication No. 2003-332214 discloses a pressuredifference formed between the accommodating parts. However, it requiresto control an interval between a connecting part that partitions twoaccommodating parts and the object to 20 μm or less for a desiredpressure difference, and the control over the pressure difference isdifficult. Moreover, Japanese Patent Application Publication No.2003-332214 sets a vacuum level of the accommodating part for theoptical system to 1×10⁻⁵ Pa or less (paragraph number 0019) and a vacuumlevel of the accommodating part for the object and mask to 1×10⁻⁴ Pa ormore (paragraph number 0020) in one example of the pressure difference.However, the inventors have discovered that this pressure condition isinsufficient to improve both the resolution and productivity.

In other words, when carbon molecules such as hydrocarbon, remain on anexposure optical path, the carbon adheres to a surface of the opticalelement due to the irradiated light, and absorbs the EUV light, causingdecreased reflectivity. Such carbon originates in an escape gas from adriving mechanism that drives the object and the mask. The prior artdoes not propose any pressure controls to prevent the carbon adhesion.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to an exposure apparatus that easilyimproves both the resolution and productivity.

An exposure apparatus according to one aspect of the present inventionincludes a projection optical system for projecting a pattern of a maskonto an object using a light with wavelength of 20 nm or less from alight source, and first and second accommodating parts for accommodatingthe projection optical system and the mask or the object, said first andsecond accommodating part has different pressures, wherein said aPs/Po≧100 and Ps≦10⁻³ Pa are met, where Po is the pressure of the firstaccommodating part, and Ps is the pressure of the second accommodatingpart.

An exposure apparatus of another aspect of the present inventionincludes a projection optical system for projecting a pattern of a maskonto an object using a light with wavelength of 20 nm or less from alight source, first and second accommodating parts for accommodating theprojection optical system and the mask or the object, said first andsecond accommodating part has different pressures, and a connecting partfor defining an opening part that connects said second accommodatingpart with said first accommodating part, wherein said connecting parthas a convex section that projects toward the object, and the convexsection includes a projecting part that bends in almost parallel to theaccommodated mask or object, and defines the opening part, and whereinsaid opening part of the connecting part has an area of 125 mm² or more,an average distance between the accomnmodated mask or object and theprojecting part is 3 mm or less, and a length of the projecting part inthe scan direction is 5.2 mm or more.

An exposure apparatus of another aspect of the present inventionincludes a projection optical system for projecting a pattern of a maskonto an object using a light with wavelength of 20 nm or less from alight source, first and second accommodating parts for accommodating theprojection optical system and the mask or the object, said first andsecond accommodating part has different pressures, and a connecting partfor defining an opening part that connects said second accommodatingpart with said first accommodating part, wherein said connecting parthas a convex section that projects toward the mask, and the convexsection includes a projecting part that bends in almost parallel to themask, and defines the opening part, and wherein said opening part of theconnecting part has an area of 2000 mm² or more, an average distancebetween the mask and the projecting part is 2 mm or less, and a lengthof the projecting part in the scan direction is 5.2 mm or more.

An exposure apparatus of another aspect of the present inventionincludes a projection optical system for projecting a pattern of a maskonto an object using a light with wavelength of 20 nm or less from alight source, first and second accommodating parts for accommodating theprojection optical system and the mask or the object, said first andsecond accommodating part has different pressures, a connecting part fordefining an opening part that connects said second accommodating partand said first accommodating part to each other, and a cooling part forcooling a member to form the opening part, wherein said a Ps≧Po is met,Po is the pressure of the first accommodating part, and Ps is thepressure of the second accommodating part.

An exposure apparatus of another aspect of the present inventionincludes a projection optical system for projecting a pattern of a maskonto an object using a light with wavelength of 20 nm or less from alight source, accommodating parts for separately accommodating theprojection optical system and the mask or the object, said accommodatingparts has different pressures, and a connecting part for having anopening part that connects accommodating parts to each other, whereinsaid connecting part has a convex section that projects from theprojection optical system to the object, and the convex section includesa projecting part that bends in almost parallel to a surface of the maskor object and defines the opening part.

An exposure apparatus of another aspect of the present inventionincludes a projection optical system for projecting a pattern of a maskonto an object using a light with wavelength of 20 mm or less from alight source, first and second accommodating parts for accommodating theprojection optical system and the mask or the object, and a connectingpart for defining an opening part that connects said secondaccommodating part and said first accommodating part to each other,wherein said first and second accommodating parts and a partition toform the opening part are separately supported.

A fabrication method of the above exposure apparatus according to stillanother aspect of the present invention includes the steps of defining apressure difference of both accommodating parts, and setting a length ofthe projecting part in a horizontal direction to the mask or the object,a distance between the projecting part and the mask or the object, andan opening area of the connecting part based on the pressure differencedefined at the defining step.

A device fabricating method according to still another aspect of thepresent intention includes step of exposing an object using the aboveexposure apparatus, and performing a development process for the objectexposed.

Other objects and further features of the present invention will becomereadily apparent from the following description of the preferredembodiments with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view of an EUV exposure apparatus of thepresent invention.

FIG. 2 is a schematic partially enlarged view of a connecting part ofthe EUV exposure apparatus shown in FIG. 1.

FIG. 3 is a graph that shows a relationship between a projecting part ofan accommodating part shown in FIG. 2 and an inside pressure.

FIG. 4 is a schematic partially enlarged view of another connecting partof the EUV exposure apparatus shown in FIG. 1.

FIG. 5 is a graph that shows a relationship between a projecting part ofan accommodating part shown in FIG. 4 and an inside pressure.

FIG. 6 is a schematic sectional view of an FUV exposure apparatus ofanother embodiment shown in FIG. 1.

FIG. 7 is a schematic sectional view of an EUV exposure apparatus ofanother embodiment shown in FIG. 1.

FIG. 8 is a flowchart for explaining how to fabricate devices (such assemiconductor chips such as ICs, LCDs, CCDs, and the like).

FIG. 9 is a detail flowchart of a wafer process in Step 4 of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the accompanying drawings, a description will be givenof an EUV exposure apparatus 1 of one aspect according to the presentinvention. Here, FIG. 1 is a structure of the exposure apparatus 1. Theexposure apparatus 1 is a projection exposure apparatus that uses, asillumination light for the exposure, EUV light (e.g., with a wavelengthof 13.4 nm) to perform a step-and-scan exposure that transfers a circuitpattern formed on a mask 20 onto an object 50. Such an exposureapparatus is suitable for a sub-micron or quarter-micron lithographyprocess. This embodiment exemplarily describes a step-and-scan exposureapparatus (which is also called “a scanner”). The “step-and-scanmanner”, as used herein, is an exposure method that exposes a maskpattern onto the object by continuously scanning the object relative tothe mask, and by moving, after an exposure shot, the object stepwise tothe next exposure area to be shot.

Referring to FIG. 1, the exposure apparatus 1 includes an illuminationapparatus 10, the mask 20, mask state 30 mounted with the mask 20, aprojection optical system 40, the object 50, a wafer stage 60 mountedwith the object 50, an alignment detecting mechanism 70, a focusposition detecting mechanism 80, a vacuum chamber 100, and a pressurecontrol apparatus 200.

The illumination apparatus 10 uses the EUV light corresponding to anarc-shaped field of the projection optical system 40 to illuminate themask 20, and includes a EUV light source 12 and an illumination opticalsystem 14.

The EUV light source 12 uses, for example, a laser plasma light source.It generates high temperature plasma by irradiating a pulsed laser beam12 a with high intensity generated from an excitation laser 12 a onto atarget material supplied from a target supply apparatus 12 b in a vacuumchamber, and uses the EUV light which has been emitted from the plasma.The target material may use a metallic thin film, a gas jet, aliquid-drop, etc. The laser beam preferably has high repetitivefrequency, e.g., usually several kHz, for increased average intensity ofthe emitted EUV light from the plasma. Alternatively., the EDV lightsource 12 may use a discharge plasma light source. The discharge plasmalight source emits gas around an electrode put in vacuum, applies pulsevoltage to the electrode for discharge, and induces high temperatureplasma. This plasma emits the EUV light to be utilized. Of course, theEUV light source 12 is not limited to them, but may use any technologyknown in the art.

The illumination optical system 14 includes a condenser mirror 14 a, anoptical integrator 14 b, a mirror 14 c, an aperture stop 14 d (forcontrolling an angle of view), and a mirror 14 e. The condenser mirror14 a condenses the EUV light that is radiated approximatelyisotropically from the laser plasma, and the optical integrator 14 buniformly illuminates the mask 20 with a predetermined aperture. Theillumination light that has passed through the optical integrator 14 billuminates the mask 20 through the mirror 14 c and mirror 14 e. Theaperture stop 14 e is arranged in a position conjugate with the mask 20,and limits an illumination area on the mask 20 to an arc-shaped.

The mask 20 is a reflection mask that forms a circuit pattern or imageto be transferred, and supported and driven by the mask stage 30. Thediffracted light from the mask 20 is reflected by the projection opticalsystem 30 and projected onto the object 40. The mask 20 and the object40 are arranged optically conjugate with each other. The exposureapparatus 1 is a scanner, and projects a reduced size of the pattern onthe mask 20 on the object 40 by scanning the mask 20 and the object 40.

The mask stage 30 supports the mask 20 through a mask chuck 32 and isconnected to a moving mechanism (not shown). The mask stage 30 may useany structure known in the art. A moving mechanism (not shown) mayinclude a linear motor etc., and drives the mask stage 30 at least in adirection X and moves the mask 20. Here, the exposure apparatus 1assigns the direction X to scan the mask 20 or the object 40, adirection Y perpendicular to the direction X, and a direction Zperpendicular to the mask 20 or the object 40.

The projection optical system 40 uses plural mirrors (multilayermirrors) 40 a to 40 c and 40 e and an aperture stop 40 d for limiting anopening, to project a reduced size of the pattern formed on the mask 20onto the object 50. The number of mirrors is about four to six. For wideexposure area with the small number of mirrors, the mask 20 and object50 are simultaneously scanned to transfer a wide area that is anarc-shaped area or ring field apart from the optical axis by apredetermined distance. Shape on a reflection surface of each mirror isa spherical surface or aspherical surface of a convex surface or concavesurface. The projection optical system 40 has a NA of about 0.1 to 0.2.

Each mirror is formed by grinding and polishing a substrate that is madeof a rigid and hard material with a small coefficient of thermalexpansion, processing the substrate into a predetermined reflectivesurface, and forming a multilayer film such as molybdenum/silicon on areflection surface that has a predetermined reflection surface shape. Ifan incident angle not over a surface of the mirror surface, thewavelength of the EUV light that provide the maximum reflectance variesaccording to locations on multilayer film with a constant film cycle.Therefore, the film cycle distribution needs to efficiently reflect theEUV light with the same wavelength on the mirror surface.

The instant embodiment uses a wafer as the object 50 to be exposed, butit may include a liquid crystal plate and a wide range of other objectsto be exposed. Photoresist is applied onto the object 50.

The wafer stage 60 supports the object 50 by a wafer chuck 62. The waferstage 60 moves the object 50, for example, using a liner motor in XYZdirections. The positions of the mask stage 30 and wafer stage 60 aremonitored, for example, by a laser interferometer, driven at a constantspeed ratio, and those position and posture are controlled.

The alignment detection mechanism 70 measures a positional relationshipbetween the position of the mask 20 and the optical axis of theprojection optical system 40, and a positional relationship between theposition of the object 50 and the optical axis of the projection opticalsystem 40, and sets positions and angles of the mask stage 30 and thewafer stage 60 so that a projected image of the mask 20 may bepositioned in place on the object 50.

The focus position detecting mechanism 80 measures a focus position inthe direction Z on the object 50 surface, and control over a positionand angle of the wafer stage 60 may always maintain the object 50surface at an imaging position of the projection optical system 40during exposure.

The vacuum chamber 100 accommodates a part of the illumination apparatus10, the mask stage 30, the projection optical system 40 and the waferstage 60 in the predetermined accommodating parts, and maintains apressure environment of each accommodating parts. The vacuum chamber 100includes plural accommodating parts 110, 112, 114, 130, 140 and 150,connecting parts 113, 115, 160 and 170. While the accommodating parts130, 140 and 150 are separate members in the instant embodiment, atleast one of the accommodating parts 140 and 150 may be separate fromthe accommodating part 130 according to the present invention. Thereby,the optical system is less contaminative than the conventional.

The accommodating part 110 accommodates a part of the illuminationapparatus 10, and is connected to the accommodating parts 112 and 114.The accommodating parts 110 and 112 are partitioned by the connectingpart 113, and both parts are connected each other through an openingpart 113 a. The accommodating parts 114 and 130 are partitioned by theconnecting part 116, and both parts are connected to each other throughan opening part 116 a. The accommodating parts 110, 112 and 114 areexhausted by the pressure control apparatus 200 described later, preventto attenuate by absorbing the EUV light to the gas, and removes adebris. The connecting parts 113, 115 and 116 prevent to adhere thedebris generated from the EUV light source and ingressed into theaccommodating part 130 to the optical element. The opening parts 113 a,115 a and 116 a guide the EUV light.

The accommodating part 130 accommodates a part of the illuminationapparatus 10 and the projection optical system 40, and maintains apredetermined pressure environment. The accommodating part 130 maintainsto the high vacuum to prevent the attenuation of the EUV light. If it isnecessary, a part of the illumination optical system 14 and theprojection optical system 40 are accommodated in separate accommodatingparts.

The inventor discovers that a partial pressure of a molecule includingcarbon to have to be maintained the pressure of at least 10⁻⁶ Pa orless, desirably 10⁻⁷ Pa or less, to effectively prevent adhering thecarbon from the molecule including the carbon to the optical element(mirror, integrator, and aperture stop, etc.) of the optical system.Therefore, the pressure that the accommodating part 130 should maintainis 10⁻⁶ Pa or less, desirably 10⁻⁷ Pa or less. In this pressure, becausethe molecular density is low, a possibility of adhering to the opticalelement of the optical system, and a decrease and irregularity of thelight intensity by an adhesion amount can be disregarded for an opticalperformance (the resolution and throughput) of the exposure apparatus.

The accommodating part 140 accommodates the mask 20, the mask stage 30,the mask chuck 32, and the moving mechanism (not shown) connected to themask stage 30, and maintains a predetermined pressure environment. Theaccommodating part 140 is exhausted by the pressure control apparatus200 described later, prevent to attenuate by absorbing the EUV light tothe gas, and prevents a lot of internal gases from flowing into theaccommodating part 130. The accommodating part 140 is connected to theaccommodating part 130 through the opening part 166 of the connectingpart 160 described later. The accommodating part 140 includes a maskchange door 142. The mask change door 142 opens when the raticle 20 iscarried into and carried out, and closes during exposing and after carryout. Although the mask change door 142 is arranged on a side surface ofthe accommodating part 140 in FIG. 1, the position is not limited. Themask change door 142 is a sealed structure to prevent an inflow of anexternal atmosphere.

The accommodating part 150 accommodates the object 50, the wafer stage30, the waiter chuck 32, the moving mechanism (not shown) connected tothe wafer stage 30, and maintains a predetermined pressure environment.The accommodating part 150 is exhausted by the pressure controlapparatus 200 described later, prevent to attenuate by absorbing the EUVlight to the gas, and prevents a lot of internal gases from flowing intothe accommodating part 130. The accommodating part 150 is connected tothe accommodating part 130 through the opening part 176 of theconnecting part 170 described later. The accommodating part 150 includesa mask change door 152. The mask change door 152 opens when the object50 is carried into and carried out, and closes during exposing and aftercarry out. Although the mask change door 152 is arranged on a sidesurface of the accommodating part 150 in FIG. 1, the position is notlimited. The mask change door 152 is a sealed structure to prevent aninflow of an external atmosphere.

The connecting part 160 decreases an inflow of a contaminant from theaccommodating part 140 to the accommodating part 130 by partitioning theaccommodating part 130 and the accommodating part 140, and controls theinflow of the contaminant from the accommodating part 140 to theaccommodating part 130 by generating a predetermined pressure differencebetween the both. The connecting part 160 defines the illumination areato the mask 20. The connecting part 160 has a shape to lack an upperpart of a pyramid. The connecting part 160 has a convex sectional shapethat projects to the mask 20 as shown in FIG. 2, the convex sectionalshape includes a horizontal part 161, an inclination part 162, and aprojecting part 164 (here, the projecting part is a part that becomesalmost parallel for the mask 20 or becomes an angle from −5 to +5degrees for the surface of the mask 20. Of course, a projecting part 174described later is a part that becomes almost parallel for the objectsuch as the wafer or becomes an angle from −5 to +5 degrees for thesurface of the wafer.). Here, FIG. 2 is a partially enlarged sectionalview of the connecting part 160 along a scan direction.

The exposure apparatus 1 is the scanner, and the mask stage 30 drives,then result of the connecting part 160 having the convex sectionalshape, the scan exposure executes while only the projecting part 164 isadjacent opposite to the mask 20. Because it has to set an interval withthe mask 20 to a predetermined distance dr only within the range of theprojecting part 164; an interval control is comparatively easy. On theother hand, if the connecting part 160 defines the opening part 166 bythe horizontal part 161, the horizontal part 161 is adjacent opposite tothe mask 20. Therefore, it is necessary to set the interval with themask 20 to the predetermined distance dr for the entire surface of thehorizontal part 161, and the interval control is difficult considering aflatness of both.

The inclination part 162 diagonally extends from the horizontal part 161at a predetermined angle. Although the inclination part 162 extends, inthe instant embodiment, symmetrically as shown in FIG. 2, the presentinvention is not limited to symmetrically. The inclination part 162extends below as shown in FIGS. 1 and 2. The purpose of this is to limitneither an incident light nor an exit light to the mask 20.

The projecting part 164 symmetrically extends from the inclination part162 to the mask 20 in almost parallel (in other words, horizontal) inFIG. 2, and defines the opening part 166. A couple of the projectingpart 164 has, in the instant embodiment, an equal length Yr as shown inFIG. 2. In this case, it is necessary to define for the length Yr togenerate the predetermined pressure difference. However, if the lengthYr is long, the projecting part 164 interferes with the surface of theobject 50 and mask 20 by pitching of the stages 30 and 60 when theopening part 166 closes the near of the surface of the object 50 andmask 20. Therefore, it is desirable that the length Yr is short. Bysetting the length Yr of the projecting part 164 equal lengthrespectively in consideration of the above pressure difference andinterference, the predetermined pressure difference can be generated,and the interference of the projecting part 164 and the surface of theobject 50 and mask 20 can be suppressed to the minimum. However, in theinstant embodiment, a couple of the projecting part 164 need notnecessarily have equal length Yr. Even if a couple of the projectingpart 164 is not equal length Yr, it only has to be substantially equal.In other words, the other length of a couple of the projecting part maybe within the range of 0.9 to 1.1 times, more desirably 0.95 to 1.05times, of the length Yr of the other projecting part.

A couple of the projecting part 164 sets, in the instant embodiment, theinterval with the mask 20 to dr. The projecting part 164 may be notnecessarily horizontally bent completely. In other words, the presentinvention includes the situation that the projecting part 164 inclines,and the situation the projecting part 164 and the inclination part 162form the curved surface. When the projecting part 164 inclines, theinterval dr between the projecting part 164 and the mask 20 iscalculated, for example, as an average of the intervals with the mask 20at each position of the projecting part 164.

A couple of the projecting part 164 reduces a conductance of a channelthat the gas from the accommodating part 140 arrives at theaccommodating part 130, and enables the form and maintenance of thepressure difference between the accommodating part 130 and accommodatingpart 140 as described later. The projecting part 164 is formed by almosthorizontally bending an edge of the inclination part 162 in the instantembodiment. A setting method for the pressure difference is describedlater.

The opening part 166 defines the illumination area to illuminate themask 20, particularity a scan exposure area. The illumination light toilluminate the mask 20 and the diffraction light from the mask 20 passthrough the opening part 166. The opening part 166 is formed like thearc shape or rectangle shape that has a predetermined width (in theinstant embodiment, Fr). The opening part 166 is the rectangle shape inthe instant embodiment. The opening part 166 is closed by a lid (notshown) to maintain the accommodating part 130 to the high vacuum whenthe mask 20 changes.

The connecting part 170 decreases an inflow of a contaminant from theaccommodating part 150 to the accommodating part 130 by partitioning theaccommodating part 130 and the accommodating part 150, and controls theinflow of the contaminant from the accommodating part 150 to theaccommodating part 130 by generating a predetermined pressure differencebetween the both. The connecting part 170 defines an exposure area onthe object 50. The connecting part 170 has a shape to lack an upper partof a pyramid. The connecting part 170 has a convex sectional shape thatprojects to the object 50 as shown in FIG. 4, the convex sectional shapeincludes a horizontal part 171, an inclination part 172, and aprojecting part 174. Here, FIG. 4 is a partially enlarged sectional viewof the connecting part 170 along the scan direction.

The exposure apparatus 1 is the scanner, and the wafer stage 60 drives,then result of the connecting part 170 having the convex sectionalshape, the scan exposure executes while only the projection part 174 isadjacent opposite to the object 50. Because it has to set an intervalwith the object 50 to a predetermined distance dw only within the rangeof the projecting part 174, an interval control is comparatively easy.On the other hand, if the connecting part 170 defines the opening part176 by the horizontal part 171, the horizontal part 171 is adjacentopposite to the object 50. Therefore, it is necessary to set theinterval with the object 50 to the predetermined distance dw for theentire surface of the horizontal part 171, and the interval control isdifficult considering a flatness of both.

The inclination part 172 diagonally extends from the horizontal part 171at a predetermined angle. Although the inclination part 172 extends, inthe instant embodiment, symmetrically as shown in FIG. 4, the presentinvention is not limited to symmetrically. The inclination part 172extends for above as shown in FIGS. 1 and 4. The purpose of this is notto limit the exposure light to the object 50.

The projecting part 174 symmetrically extends from the inclination part172 to the object 50 in almost parallel (in other words, horizontal) inFIG. 4, and defines the opening part 176. A couple of the projectingpart 174 has, in the instant embodiment, an equal length Yw as shown inFIG. 4, but the present invention need not necessarily have the equallength Yw.

A couple of the projecting part 174 sets, in the instant embodiment, theinterval with the object 50. The projecting part 174 may be notnecessarily horizontally bent completely. In other words, the presentinvention includes the situation that the protecting part 174 inclines,and the situation that the projecting part 174 and the inclination part172 form the curved surface. When the projecting part 174 inclines, theinterval dw between the projecting part 174 and the object 50 iscalculated, for example, as an average of the internal with the object50 at each positions of the projecting part 174.

A couple of the projecting part 174 reduces a conductance of a channelthat the gas from the accommodating part 150 arrives at theaccommodating part 130, and enables the form and maintenance of thepressure difference between the accommodating part 130 and theaccommodating part 150 as described later. The projecting part 174 isformed by almost horizontally bending an edge of the inclination part172 in the instant embodiment. A setting method for the pressuredifference is described later.

The opening part 176 defines the scan exposure area on the object 50.The exposure light to expose the object 50 passes through the openingpart 176. The opening part 176 is formed like the arc shape or rectangleshape that has a predetermined width (in the instant embodiment, Fw).The opening part 176 is the rectangle shape in the instant embodiment.The opening part 176 is closed by a lid (not shown) to maintain theaccommodating part 130 to the high vacuum when the object 50 changes.

The pressure control apparatus 200 controls or exhausts the pressure ofeach accommodating parts of the vacuum chamber 100. The pressure controlapparatus 200 includes a controller 210, an exhaust apparatus 220, and apressure detector 280.

The controller 210 controls an exposure timing and a carry out operationof mask 20 and object 50 based on a pressure information of theaccommodating part detected by the pressure detector 280, and warns anabnormal pressure. The pressure detector 280 is composed of pressuresensors that measures the pressure of each accommodating parts, and isarranged in the accommodating parts 130, 140 and 150.

The exhaust apparatus 220 exhausts the accommodating part thatcorresponds by always max power to the vacuum. The exhaust apparatus 220includes exhaust parts 221 to 226, the exhaust parts are respectivelyconnect with accommodating parts 110, 112, 114, 130, 140 and 150, andexhaust these accommodating parts. For example, each exhaust parts arecomposed of a turbo-molecular pump, and have an exhaust velocity of 10m³/sec or more.

The inventor discovers each internal pressure of the accommodating parts140 and 150 to be adjusted only to about 10⁻⁴ Pa with highest even ifthe exhaust parts 225 and 226 are arranged in the accommodating parts140 and 150 to generate the escape gas including the molecule includingthe carbon from the stage and the moving mechanism. It is necessary tolower the pressures of the accommodating parts 140 and 150 more than thepressure of the accommodating part 130 to completely prevent theinfluence of the escape gas, but the inventor discovers that such acomposition is difficult from the performance of the exhaust parts 140and 150. However, if pressure lowers any further, a generated amount ofthe escape gas is expected to increase. Therefore, it is undesirable toform the high vacuum to the accommodating parts 140 and 150 any further.

Then, the inventor examined that the pressure difference is formed amongrespectively of the accommodating parts 130, 140 and 150, and thepressure difference decreases the influence of the pollution of theoptical system by the escape gas. As above-mentioned, it is necessary toadjust the partial pressure of the molecule including the carbon of theexposure optical path to at least 10⁻⁶ Pa or less, desirably 10⁻⁷ Pa orless, to prevent the carbon adhesion. Then, an expressions 1 and 2 ismet, where the pressure of the accommodating parts 140 and 150 is Ps andthe pressure of the accommodating part 130 Po, because the minimum valueof Ps is about 10⁻⁴ Pa (it is desirable that Ps≦10⁻³ Pa) and Po needs10⁻⁶ Pa or less, desirably 10⁻⁷ Pa or less.Ps/Po≧100  (1)

DesirablyPs/Po≧1000  (2)

Thereby, the optical system in the accommodating part 130 can beprotected from the pollution of the escape gas. The controller 210 warnsto a user through a lamp and speaker (not shown) if judges that theabove relationship is not satisfied at exposing based on the result ofthe pressure detector 280. The controller 210 permits the exposure startif judges the above relationship is satisfied The controller 210 permitsthe open of the change doors 142 and 152 if judges the pressure of theaccommodating parts 140 and 150 is the atmospheric pressure at changing.

Referring to FIGS. 2 and 3, a description will be given of a setting oflength Yr of the projecting part 162 of the accommodating part 140, anda setting of the interval between the connecting part 160 and the mask20 and the pressure of the accommodating part 130. Here, FIG. 3 is agraph that shows a relationship between the projecting part 164 of theaccommodating part 140 and the internal pressure of the accommodatingpart 130.

First, these settings simulate using DSMC (Direct Simulation MonteCarlo) method, and select a value with the highest internal pressure ofthe accommodating part 130.

An opening of the opening part 166 is assumed to be a circular shape,and a diameter is assumed to be Fr. Moreover, a distance between themask 20 and a part of the projecting part 164 that is the nearest themask 20 is assumed to be dr (here, an area that an average of distancewith the mask 20 is dr or less is called the projecting part), and awidth of one of the projecting part of a couple of the projecting part164 installed on both side of the scan direction for the opening part isassumed to be Yr (here, the length of the projecting part installed onboth sides of the opening part is substantially assumed to be equal eachother). In this case, an exposure size on the exposure surface of themask 20 is assumed to be about 20 mm×100 mm, the diameter Fr sets to50.5 mm to be same area as the exposure size (In other words, an openingarea on the exposure surface of the mask is set to be 2000 mm² or moreof the area of the exposure size). The exhaust velocity of the exhaustapparatus 225 connected to the accommodating part 140 and the exhaustapparatus 224 connected to the accommodating part 130 is assumed to 10m³/sec.

In the instant embodiment, a desired pressure is set to be 10⁻⁹ Pa atthe accommodating part 130, and is set to be 10⁻⁴ Pa at theaccommodating part 140. In this case, how the pressure of theaccommodating part 130 changes is examined according to the value of Yrof dr=0.5 mm, 1 mm, and 2 mm. FIG. 3 shows the result. FIG. 3 adopts Yr(mm) for a lateral axis, and pressure (Pa) of the accommodating part 130for a longitudinal axis. As a result, it is necessary to satisfy Yr≧8 mmat dr≦2 mm (2Yr that is the length of the projecting part in the scandirection≧16 mm), or Yr≧1 mm at dr≦1 mm (2Yr≧2 mm) to maintain thepressure of the optical path space to 10⁻⁶ Pa or less. Next, it isnecessary to satisfy Yr≧74 mm at dr≦1 mm (2Yr≧148 mm) or Yr≧7 mm atdr≦0.5 mm (2Yr≧14 mm) to desirably maintain the pressure of the opticalpath space to 10⁻ ⁷ Pa or less.

An opening size is a slit shape similar to the exposure size originally,but is set like the circular shape in this calculation to simplify themodel of the simulation. The slit shape easily generates the pressuredifference because the conductance is usually small compared with thecircular shape. The pressure in the optical path space can be maintainedto the predetermined pressure for the opening of the slit shape in thesame area under the above condition.

The pressure difference might not be able to be maintained by existing adifference etc. around the mask 20. Therefore, a height adjusting memberto satisfy the above condition is arranged around the mask 20, and itmay be composes as satisfy the above condition during the exposure byusing around the mask.

Referring to FIGS. 4 and 5, a description will be given of a setting oflength Yw of the projecting part 174 of the accommodating part 150, anda setting of the interval between the connecting part 170 and the object50 and the pressure of the accommodating part 130. Here, FIG. 5 is agraph that shows a relationship between the projecting part 174 of theaccommodating part 150 and the internal pressure of the accommodatingpart 130.

These settings simulate using DSMC (Direct Simulation Monte Carlo)method, and select a value with the highest internal pressure of theaccommodating part 130 similar to the above-mentioned.

An opening of the opening part 176 is assumed to be a circular shape,and a diameter is assumed to be Fw (Of course, it is acceptableexcluding the circular shape. It is assumed to a diameter of a circlethat has the same area for the circular shape). Moreover, a distancebetween the object 50 and a part of the projecting part 174 that is thenearest the object 50 is assumed to be dw (here, an area that an averageof distance with the object 50 is dw or less is called the projectingpart), and a width of one of the projecting part of a couple of theprojecting part 174 installed on both side of the scan direction for theopening part is assumed to be Yw (here, the length of the projectingpart installed on both sides of the opening part is substantiallyassumed to be equal each other). In this case, an exposure size on theexposure surface of the object 50 is assumed to be about 5 mm×25 mm, thediameter Fw sets to 12.6 mm to be same area as the exposure size (Inother words, an opening area is set to be 125 mm² or more of the area ofthe exposure size on the object surface). The exhaust velocity of theexhaust apparatus 226 connected to the accommodating part 150 and theexhaust apparatus 224 connected to the accommodating part 130 is assumedto 10 m³/sec.

In the instant embodiment, a desired pressure is set to be 10⁻⁹ Pa atthe accommodating part 130, and is set to be 10⁻⁴ Pa at theaccommodating part 150. In this case, how the pressure of theaccommodating part 130 changes is examined according to the value of Ywof dw=0.6 mm, 1 mm, 1.5 mm, 2 mm and 3 mm. FIG. 5 shows the result. FIG.5 adopts Yw (mm) for a lateral axis, and pressure (Pa) of theaccommodating part 130 for a longitudinal axis. As a result, it isnecessary to satisfy Yw≧2.6 mm at dw≦3 mm (2Yw that is the length of theprojecting part in the scan direction≧5.2 mm), or Yw≧1 mm at dw≦2 mm(2Yw≧2 mm) to maintain the pressure of the accommodating part 130 to10⁻⁶ Pa or less. Next, it is necessary to satisfy Yw≧57 mm at dw≦2 mm(2Yw≧114 mm), Yw≧22 mm at dr≦1.5 mm (2Yw≧44 mm), Yw≧6 mm at dw≦1 mm(2Yw≧12 mm) or Yw≧1 mm at dw≦0.6 mm (2Yw≧2 mm) to desirably maintain thepressure of the accommodating part 130 to 10⁻⁷ Pa or less.

As above-mentioned, an opening size is a slit shape similar to theexposure size originally, but is set like the circular shape in thiscalculation to simplify the model of the simulation. The slit shapeeasily generates the pressure difference because the conductance isusually small compared with the circular shape. The pressure in theaccommodating part can be maintained to the predetermined pressure forthe opening of the slit shape in the same area under the abovecondition.

The exposure size on the exposure surface of the mask is assumed to beabout 20 mm×100 mm (area: 2000 mm²) in above-mentioned, but it ispossible to apply to a different exposure size. For example, when thearea of the exposure size on the exposure surface of the mask is assumedto be 100 to 300 mm², the lateral axis of FIG. 5 can be replace with Yr(mm). In other words, when the area of the exposure size on the exposuresurface of the mask is assumed to be 100 to 300 mm², it is necessary tosatisfy Yr≧2.6 mm at dr≦3 mm (2Yr that is the length of the projectingpart in the scan direction≧5.2 mm), or Yr≧1 mm at dr≦2 mm (2Yr≧2 mm) tomaintain the pressure of the accommodating part 130 to 10⁻⁶ Pa or less.

The pressure difference tight not be able to be maintained by existing adifference etc. around the object 50. Therefore, a height adjustingmember to satisfy the above condition is arranged around the object 50,and it may be composes as satisfy the above condition during theexposure by using around the object 50.

A fabrication method of the exposure apparatus 1 can fabricate thevacuum chamber 100 of the instant embodiment by using the above settingmethod for the length Yr of the projecting part 164 of the accommodatingpart 140, the interval between the connecting part 160 and the mask 20,the pressure of the accommodating part 130, the length Yw of theprojecting part 174 of the accommodating part 150, and the intervalbetween the connecting part 170 and the object 50, and the exposureapparatus 1 of the present invention can be fabricated by combining withthe fabrication method of the conventional exposure apparatus. As aresult, the exposure apparatus that easily improves both the resolutionand productivity can be fabricated.

Referring to FIG. 6, a description will be given of an exposureapparatus 1A that is another embodiment of the exposure apparatus 1.Here, FIG. 6 is a structure of the exposure apparatus 1A. The aboveembodiment is the method that prevents the inflow of the contaminantexisted in the accommodating parts 140 and 150 to the accommodating part130. On the other hand, the instant embodiment relates a method forsuppressing the adhesion of the particle existed in the accommodatingparts 130 to 150 to the surface of the mask 20 and object 50. Theexposure apparatus 1A of the instant embodiment is the same as thestructure of the exposure apparatus 1, but a connecting parts 160A and170A are different from the connecting parts 160 and 170 of the exposureapparatus 1. The exposure apparatus 1A further includes a coolingmechanism 180 and a supply part 190. Therefore, a description will begiven of only the cooling mechanism 180 and the supply part 190.

The connecting part 160A decreases an inflow of the contaminant from theaccommodating part 140 to the accommodating part 130 by partitioning theaccommodating part 130 and the accommodating part 140, and controls theinflow of the contaminant from the accommodating part 140 to theaccommodating part 130 by generating a predetermined pressure differencebetween the both. The connecting part 160A defines the illumination areato the mask 20. The connecting part 160A has, for example, a shape tolack an upper part of a pyramid. The connecting part 160A is composed ofa material such as resin and ceramic with low thermal conductivity inthe instant embodiment. The composition of other connecting part 160A isthe same as the connecting part 160, and the explanation is omitted.

The connecting part 170A decreases an inflow of the contaminant from theaccommodating part 150 to the accommodating part 130 by partitioning theaccommodating part 130 and the accommodating part 150, and controls theinflow of the contaminant from the accommodating part 150 to theaccommodating part 130 by generating a predetermined pressure differencebetween the both. The connecting part 170A defines an exposure area onthe object 50. For example, the connecting part 170A has a shape to lackan upper part of a pyramid. The connecting part 170A is composed of amaterial such as resin and ceramic with low thermal conductivity in theinstant embodiment. The composition of other connecting part 170A is thesame as the connecting part 170, and-the explanation is omitted.

The cooling mechanism 180 cools a temperature in the accommodating part,and includes a first cooling mechanism 181 and 182, and a second coolingmechanism 185 and 186.

The first cooling mechanism 181 is arranged at a position opposed to themask 20 of the connecting part 160A. The first cooling mechanism 181connects to a pipe of a cooling water and Peltier element (not shown)etc., and cools to a constant temperature. Generally, a temperature ofan area on the mask 20 that the exposure light is irradiated rises by anexposure heat, and rises more than the temperature of the connectingpart 160A. Then, a temperature difference is caused between theconnecting part 160A and the mask 20 during exposing. Therefore, thefirst cooling mechanism 181 is installed to be the temperaturedifference constant. Moreover, the mask 20 is controlled so that thetemperature may constant usually, but the first cooling mechanism 181may control the temperature of the mask 20. The first cooling mechanism181 may individually control the temperature of the mask 20, and may setthe temperature of the connecting part 160A at a temperature that islower than the preset temperature.

The first cooling mechanism 182 is arranged at a position opposed to theobject 50 of the connecting part 170A. The first cooling mechanism 182connects to a pipe of a cooling water and Peltier element (not shown)etc., and cools to a constant temperature. Generally, a temperature ofan area on the object 50 that the exposure light is irradiated rises byan exposure heat, and rises more than the temperature of the connectingpart 170A. Then, a temperature difference is caused between theconnecting part 170A and the object 50 during exposing. Therefore, thefirst cooling mechanism 182 is installed to be the temperaturedifference constant. Moreover, the object 50 is controlled so that thetemperature may constant usually, but the first cooling mechanism 182may control the temperature of the object 50. The first coolingmechanism 182 may individually control the temperature of the object 50,and may set the temperature of the connecting part 170A at a temperaturethat is lower than the preset temperature.

The second cooling mechanism 185 is arranged at a position near theconnecting part 160A. The second cooling mechanism 185 connects to apipe of a cooling water and Peltier element (not shown) etc., and coolsto a constant temperature. The second cooling mechanism 185 can suppressthe adhesion of the particle to the mask and wafer in wider area bycooling as well as the first cooling mechanism 181.

The second cooling mechanism 186 is arranged at a position near theconnecting part 170A. The second cooling mechanism 186 connects to apipe of a cooling water and Peltier element (not shown) etc., and coolsto a constant temperature. The second cooling mechanism 186 can suppressthe adhesion of the particle to the mask and wafer in wider area bycooling as well as the first cooling mechanism 181.

The instant embodiment shows a structure that achieves the suppressingeffect of the particle for both of the object 50 and the mask 20, butthe improvement of the productivity can be achieved by executing thepresent invention to either at least.

The supply part 190 introduces a gas into the accommodating part, andincludes a duct 191 and 192, and a valve 195 and 196. Concretely, thesupply part 190 introduces an inert gas such as He that has hightransmittance for the EUV light or hydrogen into the chamber though theduct 191 and 192, and the valve 195 and 196. In this case, eachaccommodating parts may be set to at least 5 Pa or more to achieve theeffect of heat migration to suppress the particle.

Moreover, a projection optical system space is set to pressure that islower then the stage space to maintain high transmittance in the space.

The setting of such pressure condition can be achieved by locating theconnecting part 160A and 170A, and the retice 20 and the object 50 closeto the predetermined position as explained by the above embodiment.

Such setting can suppress the particle adhesion to the mask 20 andobject 50 by the heat migration.

The duct 191 and 192 lead the gas from the supply part 190 to theaccommodating part 140 and 150, and is coupled to the supply part 190and the accommodating part 140 and 150. The leaded gas is the aboveinert gas such as He or hydrogen. The duct 191 is coupled to the supplypart 190 and the accommodating part 140, and the duct 192 is coupled tothe supply part 190 and the accommodating part 150. Therefore, becausethe accommodating part 140 and 150 are formed independently of the duct191 and 192, the gas flow can be changed respectively.

The valve 195 and 196 is used to adjust a flow rate of the gas, and isarranged in the duct 191 and 192. The valve 195 is arranged in the duct191, and the valve 196 is arranged in the duct 192. Therefore, theaccommodating part 140 and 150 can change the flow rate of the gas bythe valve 195 and 196 respectively.

In exposure, the EUV light emitted from the illumination apparatus 10illuminates the mask 20 by the optical element arranged in the vacuumenvironment, and images the pattern of the mask 20 onto the object 50surface. The instant embodiment uses an arc or ring shaped image plane,scans the mask 20 and object 50 at a speed ratio corresponding to areduction rate to expose the entire surface of the mask 20. The exposureapparatus 1 of the instant embodiment can maintain the inside of theaccommodating part 130 to Ps/Po≧100, Ps≦10⁻³ Pa by the above structure.In this pressure, because the molecular density is low, the possibilityof adhering to the optical element of the optical system, and a decreaseand irregularity of the light intensity by the adhesion amount can bedisregarded for the optical performance (the resolution and throughput)of the exposure apparatus, then the exposure apparatus 1 can suppressthe attenuation of the exposure light. As a result, the exposureapparatus 1 can improve the throughput, the resolution and productivity.

In addition, another embodiment is shown in FIG. 7. An opening partition1 connects to a wafer stage chamber 94 through a bellows BL1, andconnects to a chamber 92 that accommodates the projection optical systemthrough a bellows BL2. The opening partition 1 is fixed to a floorsurface F by a support frame, and can suppress an influence of avibration when a differential pumping is composed by the separatesupporting the each chambers and the opening partition 1.

The transfer amount of the vibration from the wafer stage chamber 94 tothe chamber 92 that accommodates the projection optical system can bedecreased even if there are not either the bellows BL1 and the bellowsBL2.

Similarly for the mask side, an opening partition 2 connects to a maskstage chamber 93 through a bellows BL3, and connects to the chamber 92that accommodates the projection optical system through a bellows BL4.The opening partition 2 is fixed to the floor surface F by a supportframe (not shown), and the mask stage chamber 93 is fixed to the floorsurface F by a support frame (not shown). Therefore, the influence ofthe vibration when the differential pumping is composed can besuppressed by the separate supporting the each chambers and the openingpartition 2.

The transfer amount of the vibration from the mask stage chamber 93 tothe chamber 92 that accommodates the projection optical system can bedecreased even if there are not either the bellows BL3 and the bellowsBL4.

Referring now to FIGS. 8 and 9, a description will be given of anembodiment of a device fabrication method using the above mentionedexposure apparatus 1. FIG. 8 is a flowchart for explaining how tofabricate devices (i.e., semiconductor chips such as IC and LSI, LCDs,CCDs, and the like). Here, a description will be given of thefabrication of a semiconductor chip as an example. Step 1 (circuitdesign) designs a semiconductor device circuit. Step 2 (maskfabrication) forms a mask having a designed circuit pattern. Step 3(wafer making) manufactures a wafer using materials such as silicon.Step 4 (wafer process), which is also referred to as a pretreatment,forms the actual circuitry on the wafer through lithography using themask and wafer. Step 5 (assembly), which is also referred to as apost-treatment, forms into a semiconductor chip the wafer formed in Step4 and includes an assembly step (e.g., dicing, bonding), a packagingstep (chip sealing), and the like. Step 6 (inspection) performs varioustests on the semiconductor device made in Step 5, such as a validitytest and a durability test. Through these steps, a semiconductor deviceis finished and shipped (Step 7).

FIG. 9 is a detailed flowchart of the wafer process in Step 4. Step 11(oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms aninsulating layer on the wafer's surface. Step 13 (electrode formation)forms electrodes on the wafer by vapor disposition and the like. Step 14(ion implantation) implants ions into the wafer. Step 15 (resistprocess) applies a photosensitive material onto the wafer. Step 16(exposure) uses the exposure apparatus 300 to expose a circuit patternfrom the mask onto the wafer. Step 17 (development) develops the exposedwafer. Step 18 (etching) etches parts other than a developed resistimage. Step 19 (resist stripping) removes unused resist after etching.These steps are repeated to form multi-layer circuit patterns on thewafer. The device fabrication method of this embodiment may manufacturehigher quality devices than the conventional one, because the exposurecan be executed in the environment with a little pollution of theoptical system.

Thus, the instant embodiment can provide the exposure apparatus thateasily improves both the resolution and productivity.

Furthermore, the present invention is not limited to these preferredembodiments and various variations and modifications may be made withoutdeparting from the scope of the present invention. Although the pressuredifference is set in consideration of only the escape gas from the stageand the moving mechanism, the pressure of the accommodating part 150 isset lower than the pressure of the accommodating part 140 aiming todecrease the pollution of the optical element with the organismgenerated from the resist of the object 50, and the condition of thepressure difference is changed. The pressure condition in this caseshould set the pressure of several Pa or more to the projection opticalsystem space.

This application claims a benefit of a foreign priority based onJapanese Patent Applications Nos. 2004-197269, filed on Jul. 2, 2004,and 2005-085663, filed on Mar. 24, 2005, each of which is herebyincorporated by reference herein in its entirety as if fully set forthherein.

1. An exposure apparatus comprising: a projection optical system forprojecting a pattern of a mask onto an object using a light withwavelength of 20 nm or less from a light source; and first and secondaccommodating parts for accommodating the projection optical system andthe mask or the object, said first and second accommodating part hasdifferent pressures, wherein said a Ps/Po≧100 and Ps≦10⁻³ Pa are met,where Po is the pressure of the first accommodating part, and Ps is thepressure of the second accommodating part.
 2. An exposure apparatusaccording to claim 1, wherein a Ps/Po≧1000 and Ps≦10⁻³ Pa are met.
 3. Anexposure apparatus according to claim 1, wherein said exposure apparatustransfers the pattern onto the object by scanning the mask and theobject in a scan direction, wherein said exposure apparatus furthercomprises a connecting part for defining an opening part that connectssaid first and second accommodating parts to each other, wherein saidsecond accommodating part accommodates the mask and the object, whereinsaid connecting part has a convex section that projects toward theaccommodated mask or object, and the convex section includes aprojecting part that bends in the scan direction, and defines theopening part, and wherein said opening part has an area of 125 mm² ormore, an average distance between the accommodated mask or object andthe projecting part is 2 mm or less, and a length of the projecting partin the scan direction is 114 mm or more.
 4. An exposure apparatusaccording to claim 1, where in a pair of projecting parts projectstoward the opening part and have substantially the same length in thescan direction.
 5. An exposure apparatus according to claim 1, whereinsaid second accommodating part accommodates the mask or the object,wherein said exposure apparatus further comprises a connecting part fordefining an opening part that connects said second accommodating partwith said first accommodating part, wherein said connecting part has aconvex section that projects toward the accommodated mask or object, andthe convex section includes a projecting part that bends in almostparallel to the accommodated mask or object, and defines the openingpart, and wherein said opening part of the connecting part has an areaof 125 mm² or more, an average distance between the accommodated mask orobject and the projecting part is 1.5 mm or less, and a length of theprojecting part in the scan direction is 44 mm or more.
 6. An exposureapparatus according to claim 1, wherein said second accommodating partaccommodates the mask or the object, wherein said exposure apparatusfurther comprises a connecting part for defining an opening part thatconnects said second accommodating part with said first accommodatingpart, wherein said connecting part has a convex section that projectstoward the accommodated mask or object, and the convex section includesa projecting part that bends in almost parallel to the accommodated maskor objects and defines the opening part, and wherein said opening partof the connecting part has an area of 125 mm² or more, an averagedistance between the accommodated mask or object and the projecting partis 1 mm or less, and a length of the projecting part in the scandirection is 12 mm or more.
 7. An exposure apparatus according to claim1, wherein said second accommodating part accommodates the mask or theobject, wherein said exposure apparatus further comprises a connectingpart for defining an opening part that connects said secondaccommodating part with said first accommodating part, wherein saidconnecting part has a convex section that projects toward theaccommodated mask or object, and the convex section includes aprojecting part that bends in almost parallel to the accommodated maskor object, and defines the opening part, and wherein said opening partof the connecting part has an area of 125 mm² or more, an averagedistance between the accommodated mask or object and the projecting partis 0.1 mm or less, and a length of the projecting part in the scandirection is 2 mm or more.
 8. An exposure apparatus according to claim1, wherein said second accommodating part accommodates the mask, whereinsaid exposure apparatus further comprises a connecting part for definingan opening part that connects said second accommodating part with saidfirst accommodating part, wherein said connecting part has a convexsection that projects toward the mask, and the convex section includes aprojecting part that bends in almost parallel to the mask, and definesthe opening part, and wherein said opening part of the connecting parthas an area of 2000 mm² or more, an average distance between the maskand the projecting part is 1 mm or less, and a length of the projectingpart in the scan direction is 148 mm or more.
 9. An exposure apparatusaccording to claim 1, wherein said second accommodating partaccommodates the mask, wherein said exposure apparatus further comprisesa connecting part for defining an opening part that connects said secondaccommodating part with said first accommodating part, wherein saidconnecting part has a convex section that projects, toward the mask, andthe convex section includes a projecting part that bends in almostparallel to the mask, and defines the opening part, and wherein saidopening part of the connecting part has an area of 2000 mm² or more, anaverage distance between the mask and the projecting part is 0.5 mm orless, and a length of the projecting part in the scan direction is 14 mmor more.
 10. An exposure apparatus comprising: a projection opticalsystem for projecting a pattern of a mask onto an object using a lightwith wavelength of 20 nm or less from a light source; first and secondaccommodating parts for accommodating the projection optical system andthe mask or the object, said first and second accommodating part hasdifferent pressures; and a connecting part for defining an opening partthat connects said second accommodating part with said firstaccommodating part, wherein said connecting part has a convex sectionthat projects toward the object, and the convex section includes aprojecting part that bends in almost parallel to the accommodated maskor object, and defines the opening part, and wherein said opening partof the connecting part has an area of 125 mm² or more, an averagedistance between the accommodated mask or object and the projecting partis 3 mm or less, and a length of the projecting part in the scandirection is 5.2 mm or more.
 11. An exposure apparatus according toclaim 10, wherein said opening part of the connecting part has an areaof 125 mm² or more, an average distance between the accommodated mask orobject and the projecting part is 2 mm or less, and a length of theprojecting part in the scan direction is 4 mm or more.
 12. An exposureapparatus comprising: a projection optical system for projecting apattern of a mask onto an object using a light with wavelength of 20 nmor less from a light source; first and second accommodating parts foraccommodating the projection optical system and the mask or the object,said first and second accommodating part has different pressures; and aconnecting part for defining an opening part that connects said secondaccommodating part with said first accommodating part, wherein saidconnecting part has a convex section that projects toward the mask, andthe convex section includes a projecting part that bends in almostparallel to the mask, and defines the opening part, and wherein saidopening part of the connecting part has an area of 2000 mm² or more, anaverage distance between the mask and the projecting part is 2 mm orless, and a length of the projecting part in the scan direction is 5.2mm or more.
 13. An exposure apparatus according to claim 12, whereinsaid opening part of the connecting part has an area of 2000 mm² ormore, an average distance between the mask and the projecting part is 1mm or less, and a length of the projecting part in the scan direction is2 mm or more.
 14. An exposure apparatus comprising: a projection opticalsystem for projecting a pattern of a mask onto an object using a lightwith wavelength of 20 nm or less from a light source; first and secondaccommodating parts for accommodating the projection optical system andthe mask or the object, said first and second accommodating part hasdifferent pressures; a connecting part for defining an opening part thatconnects said second accommodating part and said first accommodatingpart to each other; and a cooling part for cooling a member to form theopening part, wherein said a Ps≧Po is met, Po is the pressure of thefirst accommodating part, and Ps is the pressure of the secondaccommodating part.
 15. An exposure apparatus according to claim 14,wherein said cooling part includes first and second cooling parts thatcool the opening part.
 16. An exposure apparatus according to claim 14,wherein said pressure Ps of the second accommodating part is Ps≧5 Pa.17. An exposure apparatus according to claim 14, wherein a Ps/Po is met,where Po is the pressure of the first accommodating part, and Ps is thepressure of the second accommodating part.
 18. An exposure apparatusaccording to claim 14, further comprising a supply part for supplying aninert gas such as helium and argon etc.
 19. An exposure apparatuscomprising: a projection optical system for projecting a pattern of amask onto an object using a light with wavelength of 20 nm or less froma light source; accommodating parts for separately accommodating theprojection optical system and the mask or the object, said accommodatingparts has different pressures; and a connecting part for having anopening part that connects accommodating parts to each other, whereinsaid connecting part has a convex section that projects from theprojection optical system to the object, and the convex section includesa projecting part that bends in almost parallel to a surface of the maskor object and defines the opening part.
 20. An exposure apparatuscomprising: a projection optical system for projecting a pattern of amask onto an object using a light with wavelength of 20 nm or less froma light source; first and second accommodating parts for accommodatingthe projection optical system and the mask or the object; and aconnecting part for defining an opening part that connects said secondaccommodating part and said first accommodating part to each other;wherein said first and second accommodating parts and a partition toform the opening part are separately supported.
 21. A fabrication methodof an exposure apparatus according to claim 1, said fabrication methodcomprising the steps of: defining a pressure difference of bothaccommodating parts; and setting a length of the projecting part in ahorizontal direction to the mask or the object, a distance between theprojecting part and the mask or the object, and an opening area of theconnecting part based on the pressure difference defined at the definingstep.
 22. A device manufacturing method comprising the steps of:exposing an object using an exposure apparatus according to claim 1; andperforming a development process for the object exposed.